irrigations on only 44% of treatment days), with 15.5% and 12.7% of patients reporting problems with medication cost and irrigation use, respectively [48]. Adverse events related to steroid irrigation are rare, mild, and mostly localized (e.g., nasal pain, irritation, or epistaxis), and blinded RCTs reported no signicant HPA axis suppression or intraocular pressure elevations after a year of twice-daily steroid irrigations [36, 40]. However, citing concerns about the unregulated nature of ste­roid irrigations (e.g., no high-quality safety data, no aftermarket surveillance, no standardization of dosing or administration, potential variability in compounded medication), some experts have urged doctors to consider screening patients for HPA suppression and other complications of chronic glucocorticoid exposure [49].

Although off-label nasal steroid irrigation is a common clinical practice in con­temporary CRS management, there continues to be little consensus on the appropri­ate indications and optimal irrigation regimen, delivery device (e.g., neti pot vs a nasal squeeze bottle), and steroid choice (type and dose). Patient positioning during irrigations is an important factor that is often overlooked. Cadaveric studies have demonstrated signicant differences in irrigation distribution with variable head positioning [50–54], with optimal irrigation of the paranasal sinuses in the “vertex” (i.e., with nose down) or “vertex to oor” position (i.e., with Frankfort horizontal line angled >90° to the ground). The authors typically instruct patients to perform nasal rinses while leaning over a sink or basin, as this position is well tolerated by most patients. Cadaveric studies have also demonstrated signicant differences in irrigation distribution depending on the extent of surgery [50, 52, 53, 55–57]. No well-designed, randomized controlled study has demonstrated statistically signi­cant improvement in subjective or objective CRS outcomes for intranasal steroid over placebo irrigations in CRS patients in the absence of previous sinus surgery.

EDS-FLU has had demonstrable efcacy and has been well tolerated by patients in multiple studies. Reported adherence rates with EDS-FLU are as high as 97–99% during the study period [58, 59], and most patients reported that the delivery system was somewhat or very comfortable (74–82% at 1–12months) and easy to adminis­ter (85–90% at 1–12months) [60–62]. Large, double-blind, randomized placebo­controlled studies have demonstrated statistically signicant advantages of EDS-FLU over placebo in multiple objective and subjective measures in patients with CRSwNP and CRSsNP (Table22.2) [58–60, 63, 64]. Adverse events related to EDS-FLU were generally local and of mild severity and included headache, naso­pharyngitis, and septal erythema or ulceration. Epistaxis occurred in a dose­dependent rate in EDS-FLU groups across studies (1.4% [5/348] in placebo groups,

superiority of twice-daily EDS-FLU treatment over standard topical steroid thera­pies in the treatment of CRS has not been rigorously established. Nevertheless, a small prospective, uncontrolled study and one post hoc analysis of data pooled from the Navigate I and II studies both demonstrated statistically signicant improve­ments in multiple objective and subjective measures with EDS-FLU in patients with continued CRSwNP symptoms on other topical nasal steroids, including steroid irrigation [66, 67]. Additional subgroup analyses of pooled data from high-quality, randomized controlled studies have shown that twice-daily EDS-FLU treatment also improves outcomes in CRSw/sNP patients with recurrent symptoms after pre­vious sinus surgery [68, 69].

While nasal sprays, powders, and irrigations are rapidly cleared from the nasal cav­ity [23, 24], steroid-eluting sinus stents enable the sustained release of steroid com­pounds at the site of disease. Bioabsorbable, self-expanding, steroid-eluting sinus stents were originally developed to maintain sinus patency and reduce inammation after endoscopic surgery [70]. The rst FDA-approved drug-eluting sinus stents were designed for endoscopic placement in the ethmoid cavity during surgery to maintain patency and deliver steroids locally. These stents were composed of a polylactide-co-glycolide (PLGA) polymer impregnated with 370-μg mometasone furoate, a design that allows for the gradual, controlled release of steroid over a 30-day period. Animal studies with mometasone furoate-coated bioabsorbable stents demonstrated effective mucosal drug delivery, with negligible systemic absorption [70], and further studies in human subjects showed that the stents were generally well tolerated and entirely resorbed within 45–60days [71, 72].